When a telephone customer having a number of incoming telephone lines is experiencing difficulty with telephone service, the difficulty may lie in the telephone circuitry of the telephone service supplier, referred to herein as the "telephone company" or "telephone service company", or in the customer's internal telephone lines. In the event of such difficulty ordinarily the customer places a call to the telephone service supplier and requests that service personnel come to his facility and perform the repairs that are necessary. When telephone line service personnel arrive at the facility and conduct tests, the source of the difficulty is quickly determined. Heretofore, the telephone service company was responsible to deliver a proper telephone signal to the telephone instruments of the customer. In many cases these telephones are owned by the telephone service company and leased or rented by the customer. Recent changes in telephone service responsibilities have caused the telephone service company to be responsible only to deliver a proper telephone signal to the customer's facility. The customer is then responsible for maintenance of any internal telephone circuits interconnecting telephones and and other telephone equipment with the signal junction provided by the telephone service company.
In a single or multi-line telephone service installation for businesses a single network interface is placed inside the customer's premises and is typically affixed to the wall structure. To suit the needs of the customer, the network interface is typically located in a service room, storage room, closet, etc. There are several types of network interfaces in use at the present time. For example, the NWI RJ11C network interface is employed for single line applications. For two line applications, the NWI RJ14C network interface is employed. The NWI RJ25 network interface is employed when the installation incorporates three lines. Vendors may request older type interfaces such as the RJ21X, RJ31X, RJ45S and the RJ41S. The only network interface identified above that can be fully tested by the customer is the NWI RJ11C network interface. All of the other types of network interfaces will require a service call vendor or the telephone service company in order to accomplish complete testing.
In multi-line telephone service installations, a single line network interface must be installed inside the customer's location for testing and wiring simplicity. A typical network interface in present use is the NWI RJ11C which is designed for a maximum of 25 pairs of telephone lines.
If, upon inspection of the network interface by service personnel, the electrical problem is found to be in the customer's telephone lines, the customer is notified of the difficulty and receives a service charge from the telephone company for the inspection. Thereafter, the customer's own service personnel must be utilized to correct the difficulty. The customer must pay the telephone service company for the inspection and then must pay telephone repair personnel to have its telephone system repaired if internal line trouble is encountered.
Telephone service network interfaces such as that set forth in U.S. Pat. No. 4,647,725 have been developed for single line installations which incorporate test receptacles for an incoming telephone line. Integral jack connections coupled with the customer telephone circuit are received by the test receptacle of the network interface to maintain connection of customer telephone circuits with the service circuits of the telephone service company. For customer verification of the conditions of the incoming telephone circuit from the telephone service company, the integral jack is removed from the test receptacle and the connector jack of a telephone instrument is inserted into the test receptacle. If a clear dial tone is heard on the telephone handset the customer then is aware that the incoming service signal from the telephone utility company is proper and that the telephone line trouble is located in the customer lines or equipment.
Multiple line network interface modules with line testing capability have also been developed as indicated by U.S. Pat. No. 4,651,345. At the present time, however, no multiple line telephone system has been developed which incorporates facilities for line testing and which may be substituted in place of the conventional RJ21X connecting block. The only multiple-line interfaces that are presently commercially available to not provide the customer with the capability of conducting line tests and making telephone connections to the module.
It is desirable therefore to provide multiple line telephone service customers with an integral telephone network interface module which can be efficiently substituted for a conventional RJ21X connecting block and which provides a simple and efficient facility for conducting tests for each of the incoming telephone lines, thus enabling the customer to make an initial determination whether the service difficulty lies in the equipment of the telephone service company or in the customer's internal telephone circuitry. If the customer is enabled to conduct this type of test for a multiple line telephone facility without difficulty and without requiring an extraordinary level of skill, the service charge ordinarily levied by the telephone service company and the time required for service calls by service company repair personnel can be effectively eliminated. The circuit testing facility is provided at minimal exposure and without excessive clutter of equipment in the customer's telephone network area. The customer, after conducting a simple test and determining that the difficulty lies in its internal circuitry, can simply call service personnel to conduct repairs. If the difficulty is found to lie in the incoming circuitry of the telephone service company, that company can be called instead in order that its service personnel may conduct appropriate repairs at no cost to the customer.